Something New
by Devi-Yosh
Summary: Hello. My name is Chara. It's wonderful to make your acquaintance. Why don't I tell you the story of how I tricked Sans to become a beast... just... like... me? :) (Undertale AU / female Chara/Frisk / TW: suicide, excessive guilt and grief (not insanity), possible child abuse / Pacifist and Genocide Runs spoilers / contains foul language / not for the sensitive or easily offended)
1. Introduction

_Hello. My name is Chara. It's wonderful to make your acquaintance. I suppose you're wondering what's even going on here, huh? How could I possibly be alive and in control? Frisk was supposed to have overpowered you with her_ _ **determination**_ _and love and mercy so she could have her sappy little happy ending with the monsters! That's what you're thinking, right?_

 _Well, yes, that did happen... in other timelines. But not this one. This timeline has a very special place in my heart, or lack thereof rather. I wouldn't want to spoil anything for you, so instead why don't I tell you the story of how I tricked Sans to become a beast... just... like... me?_

 _:)_

* * *

 **A/N: Hi, guys! I know this introduction is SO INCREDIBLY SHORT! But it's just to spark up interest for the story ahead. I promise you all, it will be full of sadness and angst and tragedy if you're into that sort of thing, as well as trigger warnings; this story is not for the sensitive or easily offended. Oh, and a few spoilers, too, specifically on the Genocide Run.**

 **Also, this story takes place in an AU known as Something New... (formerly Insanity! but everyone really didn't like me using a serious mental condition as the topic of an AU) and it will also shortly become an ask blog on Tumblr.**


	2. The Deal

"So, let's try this again, shall we?" Chara chuckled with an evil smirk, using her shirt to wipe off the red substance on her knife - was it blood or ketchup? - as she glared at the falling skeleton before her. "I've been giving you chance after chance to consider my offer; 758 runs to be exact."

Sans panted heavily as he clutched his hand to his bleeding chest, a large gash running through his broken ribs, ripped shirt, and sliced SOUL. He shut his eyes tightly and gritted his teeth in an attempt to block out both the excruciating pain and the endless torment coming from the enemy of monsterkind and humanity alike. He had failed once again to stop this demonic child from completing yet another Genocide Run, and the familiar pang of failure tugged at his emotions.

"So, Sans?" Chara hissed eerily, casually twirling the knife in her hand. "What do you think of my offer now? Will you join me?"

Rage bubbled up in Sans, and he growled deeply. Ever since the 562nd run, this little demon child had been asking him to join her in killing all the monsters in the Underground in an attempt to switch things up and give them both something new to experience. Of course, he would always decline the offer; like he was going to kill when he was supposed to protect.

However, the falling monster found it was getting harder and harder to resist the temptations of finally accepting Chara's offer. These constant runs were beginning to drive him mad, and he was beginning to really consider not doing anything at all. After all, Chara would just RESET and start all over again. But it was always just something about how she would always kill his younger brother Papyrus. He was the sweetest, kindest, brightest monster in the Underground - the brightest creature in the universe! - yet this demon had the gall to strike him down without batting an eye every run. He was beginning to grow sick of it.

But he still wouldn't give in to her demands. He had to stay strong for everyone's sake. Even if it meant having to constantly fight a losing battle timeline after timeline for the rest of eternity.

"Forget it, you little brat," the skeletal monster grunted, pain laced in his voice. "You can cut me down a million times over and I'll still never accept your offer. So you can go fuck off."

"Language, Sansy," Chara giggled, her voice sickly sweet. "You should know better than to use such profanity in front of a child."

"You're a demon. That's all you are."

"Be that as it may, I think I just may have a new proposition you won't be too keen on ignoring." The child leaned back against a pillar and crossed her arms, never taking her smug gaze off her opponent. "What if the next run would be the last one?"

Sans had not been expecting this, and he looked up in surprise at her with widened eyes.

Chara knew he had peaked his interest and continued. "You see, just like you, I'm growing rather bored of this same exact routine: I take over Frisk's body; I kill everyone; you try to stop me; I kill you as well; I RESET; and wash, rinse, and repeat. So if you were to do this with me just this once, it would finally give me the pleasure of experiencing something new. I'd be more than grateful for your sacrifice, Sans, so grateful that I would be willing to end it all at the end of the run. I'll finally let Frisk take back control, and you all can have your happy ending."

Sans felt absolutely disgusting. He was actually considering taking up her offer now! The thought of all this torment ending if he made this one sacrifice was as appeasing as a slice of stale bread to a ravenous man. But he just had to hold out. "Never. I'll never help you. Never."

"Not even if it meant saving your brother from me?"

The skeletal monster stiffened. He had always tried to protect Papyrus from this beast, but in the end she would always strike him down. Now the offer seemed more and more appetizing by the second. He would constantly live in guilt, utterly disgusted in himself, questioning why he'd ever given in in the first place, but at least it would end this torment. If Chara really was being serious, by the end of the next run everyone will be safe. Papyrus will be safe.

"Well, it was worth a try," Chara spoke with a shrug, snapping Sans out of his thoughts. She started walking past him and down the corridor towards King Asgore's throne room. "We'll just have to try again next timeline, won't we? See you then, Sansy."

"Wait."

Chara stopped in her tracks, her smirk growing into an evil grin. She was surprised to say the least, but in a good way. It seems she had finally found a way to bargain with him and get him to join her side. Of course, it was a little too early to say for absolute certain, but her hopes were still up. She slowly turned to the falling monster behind her, who was struggling to turn himself around so he could face her. "Yes, Sansy?"

Sans' sockets were blacked out in what the child assumed was regret and silent fury, but when he spoke his voice was surprisingly level. "If... If I were to theoretically accept your offer... this next run would be the absolute last? You will stop taking over Frisk? You won't kill another monster?"

"You have my word, provide I could have yours," Chara confirmed with a little nod. "If you kill every monster in the Underground - from the smallest Moldsmal to the largest Tsunderplane and everyone in between - I will RESET and leave Frisk's body forever."

The skeletal monster stayed silent for what felt like eternity, and at first Chara thought he had finally passed despite not turning to dust yet, but sure enough he spoke again. "How do I know I can trust you?"

"Sans, we've known each other for hundreds of runs now, you know that I never break a promise no matter how terrible it may be," the child replied.

"So I kill everyone only once and you'll leave us alone."

" _Yes._ " Chara found herself growing very impatient. "Are you going to accept my offer or aren't you?"

Silence greeted her question for a good long while before Sans finally let out a heavy sigh. "If... If it means I get to protect my brother... I... I..." With a little huff he hung his head in defeat. "I'll do it..."

Chara grinned brightly. This was the moment she had been waiting for for a long time. She had finally broken him! Holding back a victorious cackle, she slowly walked up to the broken monster and knelt down on one knee before holding out a hand to him, her other hand hold the knife held behind her back. "Let's shake on it then. You kill the monsters, and I leave everyone alone once it's all over. Oh, and don't think about backing out, either, or else Papyrus will feel my wrath worse than he ever had. I'll make sure his death is slow and painful. You wouldn't want to do that to your dear brother, now would you?"

A growl rumbled deep within Sans' throat. Oh, God, how he hated this brat! But he knew this was the only way to save Papyrus. Sometimes you have to hurt the ones you love to protect them - heck, he's been doing that forever with his brother by lying to him, telling him his dead friends had just gone on vacation. He lifted a shaky hand and grabbed Chara's firmly, accepting the deal, before yanking back to glare nose-to-nose with him. His left eye light dimly flickered cyan and yellow despite most of his magic leaving him, and he spoke in the most intimidating voice he could possibly muster. "But I swear to God, you little brat, if you go back on this deal I _will_ end you. Don't you dare cheat me out."

"You have my word," Chara promised calmly, rather amused at how scary the monster was trying to make himself. Giving his hand one final shake, she let go and stood up, backing away, and watched as Sans' body finally began crumbling into dust. "I'll see you in the next timeline, Sans. Be ready. Or else your brother will feel my wrath."

After Sans' body turned to dust, the child accessed Frisk's SOUL and used her **determination** to RESET.


	3. Papyrus' Death

Sans awoke with a loud gasp. His magic sparked inside him and his left eye light violently flashed bright cyan and yellow. Once he realized he was back in his bedroom and his SOUL wasn't leaking red fluids, he allowed himself to relax. His magic fizzled out and the white lights returned to his sockets as he panted heavily.

He could easily recall the last timeline. At his moment of weakness he had accepted Chara's offer, and now it was too late to take it back. He hadn't even wanted to accept the offer; he wouldn't dream of hurting anyone, especially his brother. But he just couldn't take it anymore. He couldn't stand fighting that same losing battle again and again for no real purpose but to amuse Chara and doom himself and all of monsterkind and humanity. He had given in to the peer pressure. Just as he expected, he felt utterly disgusted in himself for not being strong enough to resist the temptations.

A loud knock on the door caused Sans to shout in alarm and he nearly jumped out of bed. He panted as he tried to calm himself down as he heard his brother's voice on the other side.

"Sans, are you okay?" Papyrus asked in concern. "I heard you scream. Did you have another bad dream?"

"Y-Yeah, you could say that." Sans stuttered. "J-Just gimme a few minutes to get ready, and I'll be right out."

"In that case, I, Master Chef Papyrus, shall prepare for you the most delectable of spaghetti breakfasts!" Papyrus declared before trotting back downstairs.

Sans' emotions began to slip out of his control, and he felt tears pricking the corners of his sockets. Papyrus, the coolest skeleton he had ever known, future member of the Royal Guard, the greatest friend any monster could ever have... was going to be killed by his own brother. He was tempted to just call in sick or declare he was too tired to work today, anything to get him out of killing Papyrus. But he knew the consequences if he did so: Chara would RESET and torture Papyrus for the rest of eternity, and as much as he'd hate to admit killing him off would be so much better than watching him constantly suffer. After all, things were going to RESET after this run anyway.

Wiping away his tears, the older brother slipped on a new clean t-shirt, as well as his trademark hoodie, and put on his slippers before making his way downstairs. He could hear water boiling from the kitchen, accompanied by Papyrus cheerfully humming along to one of his favorite hit songs by Mettaton. Trying not to think too much about his dear brother's upcoming death, he walked into the kitchen and grabbed a bottle of ketchup from the cupboard.

"Wowie, Sans!" Papyrus grinned as he stirred the boiling pot of cooking pasta. "You're out of bed much earlier than you usually are! I suppose you have the same feeling I do: the feeling that I will finally capture a human today!"

"Yep, that's right," Sans lied, masking his internal pain with his trademark lazy grin, before taking a guzzle of the sweet red condiment. "I just know you'll capture a human today, Pap. Your puzzles are recalibrated and ready for action."

"Indeed they are, Sans! But what about yours? Have you recalibrated your puzzles?"

"Nah, I was feeling pretty... tired yesterday, so I didn't get around to doing it." Sans chuckled half-heartedly before taking another swig of ketchup, expecting a familiar groan of annoyance. However, it surprised him to see Papyrus looking down at him in concern instead.

"Sans, are you feeling alright?" he asked.

"Uhh, yeah? Why do you ask?"

"Well, you kind of wasted a perfect opportunity for a bone pun just now for one thing," the taller skeletal monster replied. "It isn't like you to do that."

Sans let out a frustrated huff. He had hoped his brother wouldn't notice. Since this was the first and last day of this timeline Papyrus was going to live, he didn't exactly want to torture him with puns. Sure, Chara was going to RESET afterwards, but it didn't really matter to him. After all, he didn't want Papyrus to think he truly did hate him when the dreadful time finally came - well, anymore than he was already going to think anyway. He wanted his brother to enjoy this day as much as possible before his death. The older brother decided to shrug. "Eh, can't stay on top of absolutely every pun opportunity, right? I'll certainly get another chance later on today."

"Whoop-die-doo..." Papyrus groaned with a figurative roll of his eyes. He drained out the water from the pot and dished out two servings of spaghetti on two separate plates before drizzling them with maple syrup and cinnamon, then handed a plate to Sans. "Here you go, brother! I wanted to try something new today! It's just like pancakes, only without the pancake part. I shall call it syrup spaghetti!"

"Rolls off the nonexistent tongue quite nicely, bro," Sans chuckled. Grabbing a fork, he twirled a small bite of pasta on it and took a bite. As usual, the pasta was terribly overcooked and the texture was almost unbearable, but he sucked it up anyway. Anything to keep his brother happy on his last day. At least the cinnamon and syrup went well with it surprisingly.

After the brothers finished their breakfast, Papyrus quickly cleaned the dishes and packed the rest of the spaghetti away in a tupperware before heading out. He had insisted Sans stayed home for the day, fretting that his lack of puns all morning long was a result of a fever or something, but Sans insisted he felt fine. He couldn't afford to skip out on Chara, especially with Papyrus' safety on the line.

The entire time through the town and forest Papyrus couldn't seem to stop raving over capturing a human and presenting them to Undyne so he could join the Royal Guard. Sans knew all too well that Undyne wasn't planning on letting him on the team for a good while on account he's far too innocent and sweet; if it weren't for that, he'd definitely make it in thanks to his incredible fighting skills that could actually rival both Undyne's and his own.

By the time the younger skeletal monster finished his ranting, the two brothers had made it to Papyrus' sentry post. After bidding farewell to Sans and reminding him not to fall asleep at his station again, he began brushing the snow off his post.

Finally alone with his thoughts, though it's not to say he didn't enjoy his brother's company, Sans began his slow trek through the forest towards his own station, his head hanging as he struggled not to cry. Oh, how he was going to miss his brother so much...

"It's about time you got yourself out of bed, lazybones," a sickly familiar voice chirped from up ahead. Sans' looked up quickly to see Chara sitting in his seat behind his station, her feet propped up on the stand as she admired her knife, which now had dust coating it.

"G-Get away from there," Sans stammered, trying to keep his fear and anger under control.

The child giggled as she leaped out of the seat and walked over to the monster, twirling the knife in her hand. "I've been waiting for about ten minutes after I killed the monsters in the Ruins. Too bad you couldn't help me kill them, especially Mom. You know my mom, right? Her name is Toriel. Wasn't she your love interest in Pacifist Runs?"

Sans balled up his fists and gritted his teeth as the eye lights disappeared from his sockets in fury and grief. It was true that in past Pacifist Runs before Chara ruined them he had fallen head over heels for the former queen of the monsters. He knew that, as well as Papyrus, Toriel had been slain in Chara's Genocide Runs, and even though she didn't mean nearly as much to him as Papyrus, she still had a very special place in his heart.

"Anyway," Chara continued, "just be grateful I decided to help you out. Now you won't have to go back through the Ruins to kill all the monsters since I already did that for you. Instead, you get to kill your very first monster here in Snowdin. And guess who that monster will be?"

Sans sighed in defeat and hung his head. "I'm going to guess some poor innocent young Snowdrake or Ice Cap..."

"No, actually. For your first monster, you get to kill your brother!"

" _What?!_ " Sans exclaimed, stiffening and staring wide-eyed at the demonic child. This little brat just couldn't be serious! Did she really expect him to kill Papyrus first? If anything, he expected her to want him killed last, or at least somewhere in between. He knew he had to kill Papyrus eventually, but he just didn't expect it to be way too soon. He hadn't even finished telling him everything he wanted to say before the moment of truth. He wasn't ready to do it, he just wasn't! "H-Hold on, could we maybe save him for later at least?"

"If we wait, it'll just get harder and harder to kill him," Chara giggled. "Besides, you're my partner, and I'm the one in charge here since I'm the expert. Therefore, I as the teacher am telling you as the apprentice to do as I say or else Papyrus gets it."

"Fine, fine, okay," the skeletal monster snapped, his helplessness of the situation affecting at his patience.

"Here you go, then, partner," Chara chuckled as she handed Sans her knife, not bothering to sip off Toriel's dust from it. She smirked as she watched him shakily reach out a hand for it, and impatience made her meet him halfway by placing the blade in his grasp. His breathing began to intensify as he stared in horror at the lethal weapon now in his possession, and Chara couldn't hold back a terrifying grin that was now stretched from ear to ear across her face.

"Sans!" Papyrus' voice called from a distance, causing Sans to stiffen and whimper. Chara giggled and grinned before backing away into the trees.

"Looks like it's time to begin, partner," she hissed maliciously. "Don't forget, if you back out of this your brother will be all mine."

Sans began to violently tremble as tears built up around his eyes for the umpteenth time that day. He didn't want to do it, he didn't want to kill his brother, he didn't want to! A part of him was ready to give in to Chara's consequence just so he could save himself the awaiting grief and regret that would come straight after Papyrus' death, but that would be incredibly selfish and he would never do that to his brother. Hell, he would've never even been in this mess if he wasn't so Goddamn weak! But it's too late to go back. He had to do it even if it killed him.

"Sans!" Papyrus barked, sounding much closer now. "Where are you? I checked over my puzzles and saw you have yet to recalibrate them! Let's go, you're doing that right now! I swear, you'd better not be asleep!"

"I-I'm over here, bro," the older brother managed to croak, trying his hardest to keep his voice level as tears fell down his cheeks. He couldn't stop trembling even if he wanted to. Why did this have to happen to poor Papyrus? He did nothing wrong. It's not fair...

"Oh, there you are!" the younger brother exclaimed as he spotted Sans. He trotted over to him, but slowed to a stop when he noticed the skeletal monster trembling violently. "Sans? Are you feeling alright? It must be that fever, I told you you had one! Come along, Sans, I'm bringing you home, we can recalibrate your puzzles together tomorrow."

That broke him. Sans had never once cried in front of Papyrus, he would just always mask his depression with jokes and puns. But the bittersweet thought of spending time with his brother only to know it'll never truly happen was too much for the poor monster to handle. He hugged himself tightly and began to weep.

Papyrus obviously heard him, for now his voice had rose to a panic shrill. "S-Sans? What's wrong? Are you... crying, brother? There's nothing to be sad about, I can assure-" The taller skeletal monster stopped dead in his tracks. Upon walking closer to Sans, he could finally spot what was most likely causing him so much distress.

In his hand was a dusty knife.

"Sans?" Papyrus spoke, finding himself back away a bit uncharacteristically, his voice trembling a bit in alarm. "Where... Where did you get that knife?"

It was too late now. Papyrus spotted the tool that was to be used to end his life. Sans had better use it now before he stops himself and causes even more pain to his poor brother. Gripping the handle tightly in his fist, he forced himself to turn to his brother. He looked up slowly at him, and his heart shattered into a million pieces to see a look of utter fear and confusion etched across his typically innocent, happy face.

"I'm so sorry, Pap..." Sans rasped, feeling more tears fall down his cheeks. "Please forgive me... I'm doing this to protect you..."

"What-What do you-?"

Letting loose a distraught caterwaul, Sans threw himself at Papyrus and slashed out the blade. The younger brother managed to dodge just in the nick of time, the tip of the blade slicing through the chest plate of his battle body but not striking his rib cage.

"Sans!" Papyrus gasped. "What are you doing? Why are you attacking me?"

"Hold still, Papyrus, please!" Sans continued to attack, slashing left and right as he tried to land a final blow on his brother, but he had been practicing his dodging with Undyne recently so he was able to keep himself distanced from the knife.

Suddenly, a new weight caught Sans off guard, and he collapsed to the ground heavily. He struggled to get up, but he noticed that his SOUL had turned blue. Papyrus was using his powers on him.

"S-Sans..." Papyrus trembled, his right socket's eye light glowing bright orange. "Please... I-I don't know what has gotten into you, but... I can help. You know it to be true, brother. Just put the knife down and talk to me about it, please. If you continue this, you'll certainly regret it. I know you don't want to hurt me."

Sans found that his naïve brother was both right and wrong. No, of course he didn't want to hurt his brother, but at the same time he did, only just so that Chara could finally grant everyone freedom of her constant RESETs and Genocide Runs. He struggled against the gravity spell cast on his SOUL to stand up, but the spell just grew stronger.

"Please, Sans, I don't want to fight you..." the younger skeletal monster pleaded. "Just tell me what's wrong and we can work through it together..."

"No giving in, Sans," Chara's voice echoed from the trees. "You know what'll happen if you do."

Papyrus heard the voice as well, for he was now looking around him trying to detect the speaker. Sans quickly took this opportunity to launch a bone attack from behind, striking his brother hard and taking away about half of his HP. Crying out, Papyrus lost concentration on Sans' SOUL, allowing him the chance to hop up to his feet. He launched himself forward and, without hesitating, aimed for his brother's neck and sliced out the blade.

Everything seemed to happen in slow motion. Papyrus' entire body went limp and he slowly collapsed to his knees, his orange cape no longer flowing majestically in the wind. The younger brother's head teetered for a bit before it fell off his shoulders and landed with a soft flump into the snow. The rest of his body began to crumble and fall, turning into dust, as the head of Papyrus looked up at Sans with a look that he had never seen before on his usually happy-go-lucky face, an expression that made his entire world stop.

The usually optimistic and full-of-belief monster was portraying a look of utter sadness. Tears began to flow freely down his cheeks and into the snow as he looked up at the older brother who spent his entire life trying to make him happy, who was supposed to love and cherish and protect him as older siblings should. Using the last of his strength, Papyrus rasped the two eerie words that made Sans' heart stop. "Sans... Why...?"

Sans knew exactly how his brother felt. He felt betrayed. His own brother, out of all people in the entire world, had struck him down. He just knew Papyrus was asking himself just what he did wrong to make him act this way. He knew Papyrus was questioning how good a brother he really was if he pushed him over the edge to kill him. But he didn't do anything wrong. It was all Sans' fault, it had nothing to do with Papyrus! Nothing ever has anything to do with Papyrus, he doesn't deserve any of this!

But Papyrus doesn't know that. All he knows now is that his brother probably doesn't even love him anymore if he did such a horrible thing to him. He knows he's a horrible brother and he did something wrong that led up to this point. But most of all he knows he was powerless to stop his brother's moment of weakness when he really needed him the most. Of course, Sans doesn't blame him for this, but Papyrus doesn't know that.

"Pap..." Sans croaked through his uncontrollable sobbing, his tears falling in the snow. "I... I'm so sorry... But I'm doing this to protect you... You'll understand someday, I promise..." Using the last of his strength, he raised the knife and gripped it tightly in both hands. Letting out a heartbreaking wail, he slammed the blade down into Papyrus' cranium, cracking and shattering it instantly. Papyrus couldn't speak as his head instantly turned to dust.

The last thing Sans saw of his brother before he died was the look of utter sadness and betrayal in his eyes.

Sans had killed his own brother.


End file.
